5aBV10. Examining the effects of long-term experience using tactile
supplements to speechreading.

Typically, studies evaluating tactile supplements to speechreading are
relatively short in duration and limited to the laboratory. Results from an
ongoing 10-month study of the effectiveness of four tactile devices will be
presented. Two devices encode voice fundamental frequency (F0): One encodes F0
as rate of vibration of a single solenoid, and the other as both rate and
location of vibration on a linear array of eight solenoids. Two devices are
16-channel vibrotactile vocoders: One encodes wideband speech spectral
information, and the other encodes the F2 range of frequencies. Subjects are
adults with pre- and post-lingual profound hearing impairments and are each
assigned to use a single device for the duration of the study. Some of the
subjects assigned to the single channel F0 device are also using a wearable
version outside the laboratory. Comparisons of the effectiveness of all four
devices over long-term exposure are being conducted using both traditional
performance measures and novel measures of on-line cognitive processing. To
data, 10--20 percentage point improvements in identification of words in
sentences have been observed with the single channel device.